The TimeoutSec setting is important because pulling a docker image for the
first time takes some time and might cause a time out.

If you’re familiar with systemd service files you’ll notice that the crate
service file looks similar to a regular systemd service file. The only
difference is the [X-Fleet] section that ensures only one service named
crate@x.service is assigned per node.

Submit it to the cluster using fleet (assuming a 3 node cluster):

fleetctl submit crate@{1,2,3}.service

Start the service across the cluster (assuming a 3 node cluster):

fleetctl start crate@{1,2,3}.service

Once a crate service starts a folder named /data/crate will be created on
each CoreOS node. The crate docker image is pulled and once finished the
container launches.